Suction cleaner



4 Dec. 2l, 1937. Q L SHANK ET AL 21,103,093

SUCTION CLEANER Filed Jan. 17,"1936 2 sheetsfsheet 1 ATTO RN EY De. 21, 1937. L; SHANK ET AL 2,103,099

sucTIoN CLEANER' INVENToR cmesfm BY/WSWM,

ATTO RN EY flexed and lifted fromthe door.

Patented Dec. 2l', 1937 UNITED STATES 2.103.099 sUcrroN cLEANEn Charles L. Shank and Conrad W. Traut, North Canton, Ohio, asslznors to'The Hoover Com- AOlii North Canton, Ohio, a corporation of o Application .Tanary 1'1, 193s, semi No. 59,509

carpets by suction is primarily the result of draw-` ing the air through the upstanding i ile and into thecleaner nozzle as it passes over-the surface being cleaned. The bulk of' the vdirt removal..

however, is performed by the air passing around or beneath the edges or lips of the nozzle andnot by the air drawn directly through` the carpet due to its more or less porous texture. Hence it is important that a relatively close sealing contact be4 maintained between the carpet and the nozzle in order to obtain the most effective'cleaning. v

The force of the suction is ordinarily sufficient to lift the carpet from the ioorx and h'old it against the mouth of the nozzle, but unless there is a sealing contact entirely around the nozzle much of the cleaning effectiveness of the suction is lost due to the-leakage of air between the carpet and the nozzle, that is, air entering the nozzle without producing any cleaning effect. This leakage, however, is largely confined to the end portions of the nozzle where the resistance of the carpet to lifting effect of the suction is greater due to relatively greater areas lying beyond the eil/ds of the nozzle which have to be In short, there is a tendency for the carpet to pull away from the end of the nozzle to a considerably greater extent than elsewherea condition that lends itself to correction by increasing the suction at the end of the nozzle. This, however, is not a mattr of merely increasing the speed of thefan or increasing the area of the nozzle mouth and using a more powerful fan, but in designing the suction mouth .of ,thel nozzle so that thefsuction areas at each end are increased without necessarily increasing the total suction area, except perhaps to the limited extentA hereinafter set4 forth.

Hence, the' object of the present invention is yto provide an improved contour for the mouth oithe nozzle of a suction cleaner, which will materially increase the cleaning effectiveness of the leaner without otherwise altering its .design or vchanging its operating characteristics in any essential particular.

A preferred embodiment ,of our invention is disclosed in the accompanying drawings, in which:

Figure 1 is Aa view in side elevation of a suc'- tion cleaner with parts thereof shown in section as taken on line I I ofFigure 2,

Figure 2 is a bottom plan view of the cleaner showing the shape and construction of the nozzle mouth and parts associated therewith,

Figure 3 is a fragmentary view in side elevation of the nozzle portion of thecleaner with parts broken away to show the mounting of the bottom plate.

Referring to Figures 1 and 2, a suction cleaner to which the present invention is especially applicable, consists generally of a Wheeled casing l extended transversely throughout its forward portion to form an elongated nozzle section or chamber `2, having a downwardly opening suction mouth 3 formed in part by the forward edge of a removable bottom plate' 4 for the suction chamber 5, extending rearwardly from the nozzle 2. Immediately above the'suction chamber 5, and separated therefrom by a wall 6 is a fan 'chamber enclosing a fan l driven Adirectly by a motor enclosed within its-casing 8 supported on top of the main casing i. Extending downwardly into the suction chamber 5 and axially through a circular opening 6a (termed the fan eye) fromV the fan chamber, is an extension of the fan .hub'fla having at its lower end a pulley lb carrying a belt 9 extending forwardly through the suction chamber 5 and driving an agitator omitted. Similarly, the agitator, being of standard design, need not be described in detail except to identify the pair of beater bars I 3 '(extending throughout the length of the agitator, l each traversing an angle of degrees while following helical paths from a common meeting point at one end of kthe agitator to a meeting point at the opposite end) and two brushes Il, each lextending throughout one-half thelength of the agitator between the beater bars and one spaced 180 degrees from the other. And finally, midway the ends of the agitator4 is provided a groove Illa forming the pulley for the driving belt I. And as tothe action and'function of the 155l agitator, it is sulcient to say that it rotates at a high rate of speed, and the beater bars I3 and brushes I 4 striking the carpet produce a beating eiect that dislodges the dirt and renders it more easily removable by the suction.

Now. the nozzleopening or suction mouth 3, in accordance with the standard practice, is preferably surrounded by iiat horizontal surfaces termedv lips. Moreover, these lips are preferably shaped or stamped from sheet metal, and either fastened to the nozzle section 2 or formed integral with some other member mounted within the nozzle section. Thus for example, the rear lip of the nozzle opening or mouth is a transverse extension 4a formed integral with the front edge of the bottom plate 4 and having the form of a :dat loop as clearly shown in Figure l. Again, the end lips I5 at either end of the suction mouth 3 are formed integrally with the bearing* plates I2-I2 mounted in each end of the nozzle casing 2 for supporting the agitator shaft II. In fact, the lips I5 are merely right angular flanges along the lower edges of the bearing plates |2-I 2 which project outwardly from the ends of the nozzle as clearly shown in Figures 2 and 3. Now, as a means of anchoring the rearrnost ends of the end lips I5 to the outer ends of the rear lip 4a, the outer extremities of the latter are preferably bent `forwardly at right angles to form fingers IIb-4b, each provided with a downwardly facing notch 4c (Figure 3) adapted to engage a detent I5a fixed to the upper surfaceV of each end lip I5. In this Way the bottom plate 4 may be removed for access to the chamber 5, housing the pulley shaft 'Ia and the driving belt 9, whereupon the lips maybe again joined together when the bottom plate is replaced. And, to complete the suction mouth 3, a sheet metal lip forming member IE, generally L-shaped in section, is permanently fastened to the front upright wall of the nozzle section 2 by means of rivets I1, the extreme ends of said member being preferably curved rearwardly through an angle of 90degrees to abut the adjacent ends of the lips l5, I5. And finally, a strip of relatively soft rubber I8 extends around the three exposed sides of the nozzle section 2 and serves as a. resilient guard to protect furniture from damage by contact with the cleaner during its operation.

Referring now to the shape of the nozzle mouth or opening as it appears in Figure 2, it will be noticed first of all that it is somewhat wider throughout its end portions than at its central portion, or to state it in another way, the suction mouth gradually increases in width from its centra] portion outwardly toward its ends. Thus, if

the suction mouth is divided lengthwise into ve sections it will be found that the center or midsection is formed by two complementary parallel edges of the front and rear lips extendedinwardly to form a relatively narrow or restricted portion of the suction mouth, and which is flanked on either side by the two divergentl portions gradually increasing in width and merging into the two end sections of uniform width and of materially increased areas. It may be stated in this' connection, that the advantages of widening the end portions of the suction mouth may be attained without adopting the exact contour herein disclosed, providing the central portion of the suction mouth is somewhat narrower and the end portions correspondingly wider than would otherwise be specified for a cleaner of the same size andv rating. In short, the advantages attained are essentially the result vof altering. the shape without increasing the size or area of the suction mouth, although a limited increase in the area may also be advantageous. However, enlarging the area. of the suction mouth increases the load on the motor, but so long as the additional load does not exceed the overload capacity of the motor it is possible to take advantage of the increased cleaning effectiveness, resulting from the increase in the area of the nozzle mouth. For example, an increase of say 15% in the area of the suction mouth which increased the load on the motor only 10%, but produced an increase of '7% in thel cleaning eiectiveness of thevcle'aner, would not be. considered excessive.

Considering now the reasons for and advantages of the particular shape or contour of the suction mouth, characterized chiey by the widening of the end portions, it may be assumed at the outset that the suction produced bythe fan is uniform throughout the length of the nozzle. Hence, the direct result of widening the ends of the suction mouth is to increase the suction areas at each end oi the nozzle and thereby produce a corresponding increase in the suction or lifting force exerted uponthe carpet, lying beyond the ends of the nozzle. -In other words, the suction acting throughout a greater area exerts a greater lifting force on the carpet, thusY promoting a firmer contact at the ends of the nozzle whichy 'thereof and in alignment with the belt pulley groove Ilia. The purpose o this guard is to prevent the fringes of rugs and the like from being caught between the belt and the agitator. The guard herein disclosed is preferably made from a piece of heavy steel wirershaped to provide a pair of parallel arms terminating in a loop at its outer or free end and a pair of laterally projecting arms at its inner end, whereby the guard is pivotally anchored to the nozzle section just above vthe central portion of the lip forming member IB, so that it can be swung outwardly in order to permit the agitator I0 vto be removed. Otherwise it simply straddles the nozzle mouth to prevent the fouling of the driving belt.

Moreover, as a means for affording protection both to floor surfaces and to the cleaner, it is desirable to provide at the extreme ends of the nozzle, a .pair of ribs or ns 2|, preferably formed by depressing a short mid-section of the outer4 tached to the cleaner through a bail 25, the fan at the same time creating the necessary suction within the nozzle to draw the dust laden air into the fan chamber and thence rearwardly through an exhaust outlet 26 to a dust collecting bag 21, removably attached thereto.

Certain details of construction disclosed in connection with the suction cleaner embodying the present improvement have not been described in detail inasmuch as they have no particular rela- 75 aroaooo tionship to the invention, aside from being al- 2. In a suction cleaner`,`"the combination of a ready well known in the art. nozzle having a suction mouth deilned'by longi- Having set forth al preferred embodiment of tudinal lips and transverse end lips said longitudiour invention, we claim: nal lips having their inner edges spaced apart to 1. In a suction cleaner, the combination of.a form a relatively narrow central portion, and5 nozzlemnd suction creating'means communicatgradually diverging to form relatively vwide end ing with said nozzle, the latter having a downportions of uniform width.

wardly opening mouth gradually. increasing in width from its central portion outwardly toward -V CHARLES L. SHANK. 10 gisdetxds to form widened end portions of uniform r CONRAD W. TRAU'I. 1o 

